The Re chemotype lipopolysaccharide (LPS) from Escherichia coli D31m4 and the Rd chemotype LPS from E. coli D31m3 will be purified by a combination of DEAE cellulose column chromatography and/or silica gel thin-layer chromatography. The highly purified LPS will be methylated and finally fractionated by high performance liquid chromatography on a C18-bonded silica column and analyzed by chemical means, fast atom bombardment mass spectrometry, laser desorption mass spectrometry, plasma desorption mass spectrometry, 1H-NMR, 13C-NMR, and 31P-NMR. Using these results, we shall establish the complete structures of the several R-LPSs and determine the degree of microheterogeneity in the two preparation. The purified individual components of Rd- and ReLPS will be used in biological experiments. We shall determine the exact structural requirements for the activation of B lymphocytes form nonresponder C3H/Hej mice within the structural series of precursor IVA, monophosphoryl lipid A, diphosphoryl lipid A, ReLPS and RdLPS. We shall determine more precisely the structural requirements of the core region for the induction of IL-1 in macrophage within the structural series of ReLPS and RdLPS. Biological studies will be performed on the LPS/lipid A will be tested for the ability to inactivate suppressor T cell activity, using the low-dose paralysis mouse model. The LPS/lipid A from R. sphaeroides. The LPS/lipid A will be tested for the ability to inactivate suppressor T cell activity, using the low-dose paralysis mouse model. The LPS/lipid A from R. sphaeroides are unique in that although nontoxic, they appear to have some of the beneficial endotoxin activities. They not only might have clinical applications, but are suitable reagents for basic studies into the action of endotoxin. We shall study the solubility properties in aqueous medium of the highly purified ReLPS and its derivatives from E. coli. We shall test the theory that the monomeric LPS is the active unit that interacts with the activates B cells and macrophages in aqueous medium.